Delayed neurobehavioral
performance was observed in 36% of children in Group 3, and 25% of children
in Group 2, and none in Group 1.

"A delay of
6-10 weeks in iodine supplementation of hypothyroxinemic mothers at
the beginning of gestation increases the risk of neurodevelopmental
delay in the progeny. Public health programs should address the growing
problem of iodine deficiency among women of gestational age in developing
and industrialized nations." (more below)

The above slide accompanies the
study, "Delayed Neurobehavioral Development in Children Born to Pregnant
Women with Mild Hypothyroxinemia During the First Month of Gestation:
The Importance of Early Iodine Supplementation". The
downloadable PDF is available here.

Iodine and Children

* Iodine deficiency in children and adolescents is often
associated with goiter. The incidence of goiter peaks in adolescence and
is more common in girls. School children in iodine-deficient areas show
poorer school performance, lower IQs, and a higher incidence of learning
disabilities than matched groups from iodine-sufficient areas. A meta-analysis
of 18 studies concluded that iodine deficiency alone lowered mean IQ scores
in children by 13.5 points. In-other-words, having full iodine sufficiency
has been shown to increase IQ by up to 13.5 points.

* Lower IQ of 12-13.5 points are seen in iodine deficient
populations, whereas iodine supplementation before or during early pregnancy
generally increases developmental scores in young children by 10-20%.

* The IQ of a child is set between age 2-3. Therefore,
it is essential to keep giving nursing mothers iodine until the child
is weaned.

How adding iodine to salt made America
smarter
Monday, Feb 10 2014

* The U.S. introduced iodized
salt in 1924
* A new study compares IQ results of people in iodine deficient areas
before and after iodized salt
* Americans born in iodine deficient areas showed an IQ increase of
15 points after 1924
* Iodine deficiency causes goiter and mental and physical retardation
in infants

A new study indicates that Americans gained up to 15 IQ
points after the addition of iodine to salt became mandatory.

In an effort to prevent goiter related to iodine deficiency,
authorities ruled that iodine be added to U.S. salt products in 1924.

The iodine, in addition to eliminating goiter, appears
to have had an unexpected result: smarter Americans.
In a report published in the National Bureau of Economic Research, James
Freyer, David Weil and Dimitra Politi examined data from about two million
enlistees for World War II born between 1921 and 1927, comparing the intelligence
levels of those born just before 1924 and those born just after.

To do this, they looked to standardized IQ tests that
each recruit took as a part of the enlistment process.
While the researchers didn't have access to the test scores themselves,
they had another way of gauging intelligence levels: smarter recruits
were sent to the Air Forces, while the less intelligent ones were assigned
to the Ground Forces.

Next, the economists worked out likely iodine levels in
different cities and towns around America using statistics gathered after
World War I on the occurrence of goiter.

Matching the recruits with their hometowns showed researchers
that the men from low-iodine areas made a huge leap in IQ after the introduction
of iodine.

The men born in low-iodine areas after 1924 were much
more likely to get into the Air Force and had an average IQ that was 15
points above that of their slightly older comrades.

This averages out to a 3.5 point rise in IQ levels across
the nation.

The World Health Organization backed up these results
saying:

'For iodine-deficient communities, between 10 and 15 IQ
points may be lost when compared to similar but non-iodine-deficient populations.'

Iodine comes from food sources, and is found in seafood
and foods grown in coastal areas with high levels of iodine in the soil.

Mountainous and inland areas are often very low in the
nutrient, meaning food grown there doesn't have enough iodine.

Today, iodine deficiency is the leading cause of preventable
mental retardation in the world. The condition, known as cretinism, was
also common in the U.S. until the introduction of iodized salt. [And since
Americans have reduced or eliminated iodized table salt, sub-clinical
and clinical hypothyroidism is on the rise, and so are stupid movies,
TV shows, and commercials, and antisocial behavior... coincidence? 
Don]

Originally, U.S. authorities wanted to reduce the incidence
of goiter, but research since that time has shown that iodine plays an
important role in brain development, especially during gestation.

The World Health Organization estimates that two billion
people worldwide are at risk of iodine deficiency. And it's not just a
Third World problem  the WHO reports that only 27 per cent of households
in Europe have access to iodized salt.

The researchers say that iodine may also be a cause of
the so-called Flynn Effect, the steady rise in IQ that's been ongoing
since the 1930s. But the Flynn Effect works both ways, and now, since
people in the U.S. have been avoiding table salt, which was the way iodine
became part of our diet, IQs will be dropping, and cognition will be negatively
affected. See How
Adding Iodine to Salt Made America Smarter.